In integration circuit fabrication, the antifuse and the fuse are widely used for fault tolerance. For example, the antifuse and the fuse may be placed in circuit paths in a device. An originally conductible circuit path may be broken or become an open circuit by blowing a fuse. In contrast, an originally unconductible circuit path may become a short circuit by blowing an antifuse. In addition, the antifuse is also used for one-time programming.
One type of antifuse structure is comprised of two conductors separated from each other by an insulator. The two conductors are separately connected to different components. The path between the two conductors is an unconductible circuit path, i.e., an open circuit, when the applied voltage is lower than a programming voltage. When the programming voltage is applied, the insulator undergoes a dielectric breakdown process. A leakage current increases and a thermal runaway condition develops, melting the insulator and adjacent conductive materials. The conductive materials flow from the two conductors and form a conductive filament, resulting in a short circuit between the two conductors.
The programming voltage is a critical factor in the design rule of the antifuse, and the present disclosure provides an antifuse structure which may be programmed with an appropriate programming voltage.
This Discussion of the Background section is for background information only. The statements in this Discussion of the Background are not an admission that the subject matter disclosed in this section constitutes prior art to the present disclosure, and no part of this section may be used as an admission that any part of this application, including this Discussion of the Background section, constitutes prior art to the present disclosure.